(See also wiki article Galatia_(Roman_province)
GALATIA is a Greek word, derived from Galatae the Greek name for the Gauls who invaded Asia Minor in the year 278-277 BC. (Lat. Gallograeci [='Greek Gauls'], to distinguish them from their kindred who lived in France and Northern Italy). These Gauls had been ravaging the south-eastern parts of Europe, Greece, Macedonia, and Thrace, and crossed into Asia Minor at the invitation of Nicomedes, king of Bithynia. Part of the same southward tendency appears in their movements in Italy and their conflicts with the Romans in the early centuries of the Republic. Those who entered Asia Minor came as a nation with wives and families, not as mercenary soldiers. After some fifty years' raiding and warring, they found a permanent settlement in north-eastern Phrygia, where the population was un-warlike. Their history down to the time of the Roman Empire may be studied in Wm. Ramsay's Histor. Com, on Galatians, pp. 45 ff. They continued throughout these two centuries to be the ruling caste of the district, greatly outnumbered by the native Phrygian population, who, though in many respects an inferior race, had a powerful influence on the religion, customs, and habits of the Gauls, as subject races often have over their conquerors. The earlier sense of the term Galatia is, then, the country occupied by the Gaulish immigrants, the former northeastern part of Phrygia, and the term Galatae is used after the occupation to include the subject Phrygians as well as the Galatae strictly so called (e.g. 1 Mac.8.2, where RSV reads 'Gauls').
About 160 BC the Gauls acquired a portion of Lycaonia on their southern frontier, taking in Iconium and Lystra. About the same time also they had taken in Pessinus in the NW. These and other expansions they ultimately owed to the support of Rome. From 64 BC Galatia was a client state of Rome. At the beginning of that period it was under three rulers; from 44 BC it was under one only. Deiotarus, the greatest of the Galatian chiefs, received Armenia Minor from Pompey in 64 BC Mark Antony conferred the eastern part of Paphlagonia on Castor as sole Galatian king in 40 BC, and at the same time gave Amyntas a kingdom comprising Pisidic Phrygia and Pisidia generally. In 36 BC, Castor's Galatian dominions and Pamphylia were added to Amyntas' kingdom. He was also given Iconium and the old Lycaonian tetrarchy, which Antony had formerly given to Polemon. After the battle of Actium in 31 BC, Octavian conferred on Amyntas the additional country of Cilicia Tracheia. He had thus to keep order for Rome on the south side of the plateau and on the Taurus mountains. He governed by Roman methods, and, when he died in 25 BC, he left his kingdom in such a state that Augustus resolved to take the greater part of it into the Empire in the stricter sense of that term, and made it into a province which he called Galatia. This is the second sense in which the term Galatia is used in ancient documents, namely, the sphere of administrative responsibility which included the ethnic districts, Paphlagonia, Pontus Galaticus, Galatia (in the original narrower sense), Phrygia Galatica, and Lycaonia Galatica (with 'the Added Land,' part of the original Lycaonian tetrarchy). Galatia, as a province, means all these territories together, under one Roman governor, and the inhabitants of such a province, whatever their race, were, in conformity with invariable Roman custom, denominated by a name etymologically connected with the name of the province. Thus Galatae ('Galatians') has a second sense, in conformity with the second sense of the term Galatia: it is used to include all the inhabitants of the province (see the first map in the above-mentioned work of Ramsay).
The word 'Galatia' occurs three times in the NT (1Co.16.1, Gal.1.2, and 1P.1.1). A possible fourth case (2Ti.4.10) must be left out of account, as the reading there is doubtful. There is an alternative 'Gallia,' which, even if it be not the original, suggests that the word 'Galatia' there should be taken in the sense of 'Gallia' (that is, France). It is beyond doubt that in the passage of 1 Peter the word must be taken in the sense of the province. The bearer of the letter evidently landed at some port on the Black Sea, perhaps Sinope, and visited the provinces in the order in which they appear in the address of the letter:- Pontus, Galatia, Cappadocia, Asia, and Bithynia, taking ship again at the Black Sea for Rome. The Taurus range of mountains was always conceived of as dividing the peninsula of Asia Minor into two parts, and St. Peter here appears as supervising or advising the whole body of Christians north of the Taurus range. (The effect of taking 'Galatia' in the other sense would be to leave out certain Pauline churches, Derbe, Lystra, Iconium, and Pisidian Antioch, and perhaps these alone, in all that vast region: which is absurd). With regard to the two passages in St. Paul, the case is settled by his unvarying usage. It has been noted that, proud of his Roman citizenship, he invariably uses geographical terms in the Roman sense, and that he even does violence to the Greek language by forcing the Latin names for 'Philippians' (Ph.4.15) and 'Illyricum' (Ro.15.19) into Greek, and passes by the proper Greek term in each case. We are bound, therefore, to believe that he uses 'Galatia' in the Roman sense, namely in the meaning of the Roman province as above defined. (This province had, as we have seen, 'Galatia' in the narrower and earlier sense as one of its parts). It follows, therefore, that he uses 'Galatians' (Gal.3.1) also in the wider sense of all (Christian) inhabitants of the province, irrespective of their race, as far as they were known to him.
In order to discover what communities in this vast province are especially addressed by the Apostle in his Epistle, it is necessary to make a critical examination of the only two passages in Acts which afford us a clue (16.6, 18.23). It is important to note that St. Luke never uses the term 'Galatia' or the term 'Galatians,' but only the adjective 'Galatic' (16.6, 18.23). In 16.6 the rules of the Greek language require us to translate:- 'the Phrygo-Galatic region' or 'the region which is both Phrygian and Galatian'; that is, 'the region which according to one nomenclature is Phrygian, and according to another is Galatian.' This can be none other than that section of the province Galatia which was known as Phrygia Galatica, and which contained Pisidian Antioch and Iconium, exactly the places we should expect St. Paul and his companions to go to after Derbe and Lystra. In 18.23 the Greek may be translated either 'the Galatico-Phrygian region' or 'the Galatian region and Phrygia,' preferably the latter, as it is difficult otherwise to account for the order in the Greek. 'The Galatian region,' then, will cover Derbe and Lystra; 'Phrygia' will include Iconium and Pisidian Antioch. We conclude then that, whether any other churches are comprised in the address of the Epistle to the Galatians or not - and a negative answer is probably correct - the churches of Derbe, Lystra, Iconium, and Pisidian Antioch are included. There is not a scrap of evidence that St. Paul had visited any other cities in that great province. [Article: Dictionary of the Bible, J.Hastings, 2nd Ed., T&T.Clark, 1963 - A. So.]